Inclusive photon production in pA and AA collisions at 200-GeV/u

Åkesson, T.; Almehed, S.; Angelis, A. L. S.; Armenise, N.; Atherton, H.; Aubry, P.; Bartels, H. W.; Beaudoin, G.; Beaulieu, J. M.; Beker, H.; Benary, O.; Bettoni, D.; Bisi, V.; Blevis, I.; Bøggild, H.; Cleland, W.; Clemen, M.; Collick, B.; Corriveau, F.; Dagan, S.; Dederichs, K.; Dell'Uomo, S.; Depommier, P.; Devenish, R. C. E.; Di Liberto, S.; Digiacomo, N.; Dodd, J. R.; Dogolshein, B.; Drees, A.; En'Yo, H.; Erlandsson, B.; Esten, M. J.; Fabjan, C. W.; Fischer, P.; Fraenkel, Z.; Gaidot, A.; Gibrat Debu, F.; Giubellino, P.; Glässel, P.; Goerlach, U.; Haglund, R.; Hamel, L. A.; van Hecke, H.; Hedberg, V.; Heifetz, R.; Hölscher, A.; Jacak, B.; Jarlskog, G.; Johansson, S.; Kraner, H.; Kroth, V.; Lamarche, F.; Leroy, C.; Lissauer, D.; London, G.; Lörstad, B.; Lounis, A.; Martelli, Filippo; Marzari Chiesa, A.; Masera, M.; Mazzoni, M. A.; Mazzucato, E.; Mccubbin, M. L.; Mccubbin, N. A.; Mcgaughey, P.; Meddi, F.; Mjörnmark, U.; Muciaccia, M. T.; Muraviev, S.; Murray, M.; Neubert, M.; Nilsson, S.; Olsen, L.; Oren, Y.; Pansart, J. P.; Park, Y. M.; Pfeiffer, A.; Piuz, F.; Polychronakos, V.; Poulard, G.; Price, M.; Rahm, D.; Ramello, L.; Riccati, L.; Romano, G.; Rosa, G.; Sandor, L.; Schukraft, J.; Sekimoto, M.; Sellden, B.; Seman, M.; Shmeleva, A.; Sidoroy, V.; Simone, S.; Sirois, Y.; Sletten, H.; Smirnov, S.; Soltani, J.; Sondheim, W.; Specht, H. J.; Stumer, I.; Sunier, J.; Toherniatin, V.; Thodberg, H. H.; Thompson, J.; Tikhomirov, V.; Tserruya, I.; Vasseur, G.; Veenhoff, R.; Wigmans, R.; Yepes, P.

Inclusive photonp ⊥ spectra were measured with 200 GeV/u proton,16O and32S beams on W and Pt targets, using a conversion method. The measurement of charged pions in the same apparatus allows a comparison of the γ data with the expected γ's from hadronic decays π0, η, η', ω). In all data sets, no deviation from the expected shape is observed in the range of 0.1<p ⊥<1.5 GeV/c. The number of photons normalized to pions agrees within the statistical (4%–11%) and systematical (9%) errors with the number of photons expected from hadronic decays in the integrated ranges ranges ofp ⊥>0.1 GeV/c andp ⊥>0.6 GeV/c.